In recent years, effective application of artificial insemination has become established as a proven method for improving the production of domestic livestock. Generally, such techniques provide livestock managers with an enhanced ability to selectively breed a single male to a large number of females. Selective breeding, of course, allows the production of livestock with improved genetic traits. Artificial insemination techniques also decrease the chance of diseases and physical injury formerly associated with the natural breeding process. As a result of these and other advantages, the use of artificial insemination has become a widespread technique in the management of many forms of domestic livestock.
Not surprisingly, then, a large number of varying techniques have been developed for the artificial insemination of livestock. The simplest and most common of these techniques is known as vaginal artificial insemination, or VAI. VAI has the advantage of being relatively inexpensive. VAI also requires little operator expertise or training. Unfortunately, VAI techniques are generally effective only when used in combination with relatively large amounts of freshly collected semen. In particular, VAI techniques have proven to be relatively ineffective when applied to sheep, especially when frozen semen is utilized.
Transcervical artificial insemination, or TAI, has been developed as an alternative to VAI techniques. When compared to VAI, TAI offers an alternative procedure for using frozen or fresh semen. TAI techniques also generally require fewer spermatozoa than VAI methods. Unfortunately, TAI techniques are more expensive and require more training than traditional VAI methods and present extremely variable results. Additionally, TAI techniques also present a risk of trauma to the subject animal.
Laparoscopic artificial insemination, or LAI, is another technique developed as an alternative to more traditional insemination techniques. In comparison to VAI, or TAI, LAI, offers the highest rate of pregnancy. LAI also requires the smallest number of spermatozoa per procedure. LAI is, however, an invasive and traumatic surgical procedure requiring a highly trained and licensed veterinarian. LAI also has the highest trauma risk potential.
In general, each of the preceding techniques has been applied to a number of differing types of livestock. For example, VAI, TAI and LAI methods been utilized for sheep as well as goat applications. It should be appreciated, however, that each of the preceding techniques may be more, or less, effective when utilized for a particular species. Practice has also shown that applications involving sheep are particularly problematic. In particular, female sheep, or ewes, have a cervical anatomy which includes four to six cervical rings. The rings function as partial seals for the cervical canal making traversal of the canal during an artificial insemination procedure problematic and often, ineffective. The presence of the cervical rings also increases the risk of traumatic injury during the artificial insemination procedure.
A second difficulty associated with the artificial insemination of sheep is caused by chemical incompatibility between the cervical secretions of a ewe and cryoprotectants used to preserve spermatozoa. In more detail, it is generally the case that spermatozoa are combined with a cryoprotectant and frozen prior to implantation during an artificial insemination procedure. Freezing, of course, allows the spermatozoa to be stored for long periods of time without loss in potency. Freezing can only be accomplished, however, if a cryoprotectant is added to preserve the spermatozoa during the freezing process. Unfortunately, the cryoprotectants generally available are chemically incompatible with the chemical environment present in the cervix of a sheep. The resulting chemical reaction destroys the majority of the implanted spermatozoa defeating the object of the insemination procedure.
In light of the above, it is an object of the present invention to provide a system and method for artificial insemination which minimizes the risk of trauma to the subject undergoing insemination. Another object of the present invention is to provide a system and method for artificial insemination which minimizes the level of skill and training required for successful operation. Yet another object of the present invention to provide a system and method for artificial insemination which maximizes the rate of successful insemination. Another object of the present invention to provide a system and method for artificial insemination which minimizes the amount of spermatozoa required for successful insemination. Another object of the present invention is to provide a non-surgical system and method for artificial insemination which is adaptable to the insemination of female sheep. Still another object of the present invention is to provide a system and method for artificial insemination which is relatively simple to use, easy to manufacture, and cost effective.